Laptop Jacks soldering & de-soldering techniques Soldering of electronic components is undertaken with a fine-pointed soldering iron of 15-30W and a rosin core solder of small diameter. The solder contains 60% lead and 38% tin and tiny cores of flux. When these are heated they helps the molten solder to flow more easily over the joint. A convenient small wet sponge is used to clean the iron tip and cool it between soldering sessions.
The surfaces to be soldered have to clean and free from anything like grease, oxidation or other contamination that would prevent a strong bond. It?? a mistake to heat the components too much ??just a light touch with the soldering tip should be enough to achieve a good connection.
You then apply a light coat of solder to both contacts (the connector contact and the solder pad on the circuit board. This is called ??inning??and gives them the idea soldering surface. You will also tin the tip of the iron to help conduct heat to the components.
Now you bring the component lead close to the solder pad. You heat the tip of the solder strand and immediately bring it into contact with both sides. This causes the solder to flow freely at the point of contact. Don?? use the tip of the soldering iron.
As soon as the surface of the pad has been completely coated, remove the soldering iron and resist the temptation to add more solder. The joint should not be moved until it has cooled down, otherwise it becomes a cold joint (poor metal connection).
Finally, clean the tip of the soldering iron with a damp sponge after each solder. To clean the solder off a circuit board, use a solder wick.
The soldering process dissolves some of the base metals. Even if it becomes liquid, it will not have the strength necessary to create a new bond. In fact, you can tell any reheated old solders because they have a brittle cold solder joint with a crystalline appearance.
If you wish to remove older solder from a board you should use a desoldering wick. This has plenty of flux to lift the contamination from the copper trace as well as any device leads that are present. The process also leaves a bright and shiny surface that will readily accept resoldering.
Solder has a lower melting point than the base metal so it can be safely removed. All surfaces should be ??inned??with new solder to prepare for a new solder bond.
To avoid soldering defects, it is important not to overheat the solder flux, to select the right flux and to ensure that all elements to be joined are clean. Nothing is more discouraging than to find a circuit board start to malfunction over time because it contains one or more ??old solder??joints.
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